On 10/11/16 at 02:50pm, Tong Li wrote:
This is a short documentation on how to setup kdump on live images.
All steps
was tested on Fedora 25 Alpha LiveCD and successfully saved vmcore captured
by kdump to a USB stick.
Signed-off-by: Tong Li <tonli(a)redhat.com>
---
kdump-live-images.txt | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
create mode 100644 kdump-live-images.txt
diff --git a/kdump-live-images.txt b/kdump-live-images.txt
new file mode 100644
index 0000000..32f4d2d
--- /dev/null
+++ b/kdump-live-images.txt
The file name is misleading, how about live-image-kdump-howto.txt
@@ -0,0 +1,25 @@
+Kdump now can work on Live images, but some manual configurations are needed.
How about simpler sentence below:
"Kdump works on live images with some manual configurations."
+Here is the step by step guide. Please use root privilege.
No need to mention about the root privilege here..
+
+0. (if you are using old versions of kexec-tools)
Although I like start with '0' I think we still need refer to other
kdump documentation and be consistent. Seems we have been using 1), 2)..
Could you follow and use same format?
Btw, no need mention the old versions steps, because I assume this patch
depends on the previous patch to drop root=live:
+ Apeend "root" to KDUMP_COMMANDLINE_REMOVE variable in
/etc/sysconfig/kdump
+
+Live images are booted with a kernel parameter which looks like
+"root=live:CDLABEL=Fedora-WS-Live-25_A-2". This argument can't be
recognized
+by dracut during kdump process and will cause failure of kdump. So we need
+to make sure 'root' parameter is removed during kdump process.
Above paragraph can be dropped because of the privous patch.
+
+1. Change dump target in /etc/kdump.conf
+
+When kdump is triggered in a Live environment, the default target /var/crash
+will not be mounted and unable to be used to save vmcore. You can modify it to
+make kdump save the captured dump file on an external disk or send it with ssh
+throught network.
+will not be mounted and unable to be used to save vmcore. You can
modify it to
+make kdump save the captured dump file on an external disk or send it
with ssh
+throught network.
When kdump kernel boots in a live environment, the default target
/var/crash is in in ram so you need change the dump target to an
external disk or an network dump target.
+
+2. Run 'kdumpctl start' to build kdump initramfs and start kdump.
+
+Here is all configurations you need to tweak manually. If you want to confirm
+whether kdump is working or not, you can use sys-trigger interface by running:
Change above 2 lines to below should be enough:
3) Trigger a kdump test:
+
+ $ echo 1 > /proc/sys/kernel/sysrq
+ $ echo c > /proc/sysrq-trigger
_______________________________________________
kexec mailing list -- kexec(a)lists.fedoraproject.org
To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org
Seems the crashkernel setup is missing, it should be the first step:
1) Enable crashkernel reservation
...
I do not now if livcd can have a config file so that we can boot with
an appended cmdlien params, does Fedora live supports that?
Thanks
Dave